Mixing GPU and CPU atomics does not work unless a strict migration
policy of GPU atomics must be device memory. Enforce a policy of must be
in VRAM with a retry loop of 2 attempts, if retry loop fails abort
fault.
v2:
- Only retry migration on atomics
- Drop alway migrate modparam
v3:
- Only set vram_only on DGFX (Himal)
- Bail on get_pages failure if vram_only and retry count exceeded (Himal)
- s/vram_only/devmem_only
- Update xe_svm_range_is_valid to accept devmem_only argument
v4:
- Fix logic bug get_pages failure
Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimi...@intel.com>
Signed-off-by: Matthew Brost <matthew.br...@intel.com>
---
drivers/gpu/drm/xe/xe_module.c | 3 --
drivers/gpu/drm/xe/xe_module.h | 1 -
drivers/gpu/drm/xe/xe_svm.c | 89 +++++++++++++++++++++++++---------
drivers/gpu/drm/xe/xe_svm.h | 5 --
4 files changed, 65 insertions(+), 33 deletions(-)
diff --git a/drivers/gpu/drm/xe/xe_module.c b/drivers/gpu/drm/xe/xe_module.c
index 05c7d0ae6d83..1c4dfafbcd0b 100644
--- a/drivers/gpu/drm/xe/xe_module.c
+++ b/drivers/gpu/drm/xe/xe_module.c
@@ -33,9 +33,6 @@ struct xe_modparam xe_modparam = {
module_param_named(svm_notifier_size, xe_modparam.svm_notifier_size, uint,
0600);
MODULE_PARM_DESC(svm_notifier_size, "Set the svm notifier size(in MiB), must
be power of 2");
-module_param_named(always_migrate_to_vram, xe_modparam.always_migrate_to_vram,
bool, 0444);
-MODULE_PARM_DESC(always_migrate_to_vram, "Always migrate to VRAM on GPU
fault");
-
module_param_named_unsafe(force_execlist, xe_modparam.force_execlist, bool,
0444);
MODULE_PARM_DESC(force_execlist, "Force Execlist submission");
diff --git a/drivers/gpu/drm/xe/xe_module.h b/drivers/gpu/drm/xe/xe_module.h
index 84339e509c80..5a3bfea8b7b4 100644
--- a/drivers/gpu/drm/xe/xe_module.h
+++ b/drivers/gpu/drm/xe/xe_module.h
@@ -12,7 +12,6 @@
struct xe_modparam {
bool force_execlist;
bool probe_display;
- bool always_migrate_to_vram;
u32 force_vram_bar_size;
int guc_log_level;
char *guc_firmware_path;
diff --git a/drivers/gpu/drm/xe/xe_svm.c b/drivers/gpu/drm/xe/xe_svm.c
index 890f6b2f40e9..f749ae367a8f 100644
--- a/drivers/gpu/drm/xe/xe_svm.c
+++ b/drivers/gpu/drm/xe/xe_svm.c
@@ -650,9 +650,11 @@ void xe_svm_fini(struct xe_vm *vm)
}
static bool xe_svm_range_is_valid(struct xe_svm_range *range,
- struct xe_tile *tile)
+ struct xe_tile *tile,
+ bool devmem_only)
{
- return (range->tile_present & ~range->tile_invalidated) & BIT(tile->id);
+ return ((range->tile_present & ~range->tile_invalidated) &
BIT(tile->id))
+ && (!devmem_only || range->base.flags.migrate_devmem);
}
#if IS_ENABLED(CONFIG_DRM_XE_DEVMEM_MIRROR)
@@ -726,6 +728,35 @@ static int xe_svm_alloc_vram(struct xe_vm *vm, struct
xe_tile *tile,
}
#endif
+static bool supports_4K_migration(struct xe_device *xe)
+{
+ if (xe->info.vram_flags & XE_VRAM_FLAGS_NEED64K)
+ return false;
+
+ return true;
+}
+
+static bool xe_svm_range_needs_migrate_to_vram(struct xe_svm_range *range,
+ struct xe_vma *vma)
+{
+ struct xe_vm *vm = range_to_vm(&range->base);
+ u64 range_size = xe_svm_range_size(range);
+
+ if (!range->base.flags.migrate_devmem)
+ return false;
+
+ if (xe_svm_range_in_vram(range)) {
+ drm_dbg(&vm->xe->drm, "Range is already in VRAM\n");
+ return false;
+ }
+
+ if (range_size <= SZ_64K && !supports_4K_migration(vm->xe)) {
+ drm_dbg(&vm->xe->drm, "Platform doesn't support SZ_4K range
migration\n");
+ return false;
+ }
+
+ return true;
+}
/**
* xe_svm_handle_pagefault() - SVM handle page fault
@@ -750,12 +781,15 @@ int xe_svm_handle_pagefault(struct xe_vm *vm, struct
xe_vma *vma,
IS_ENABLED(CONFIG_DRM_XE_DEVMEM_MIRROR),
.check_pages_threshold = IS_DGFX(vm->xe) &&
IS_ENABLED(CONFIG_DRM_XE_DEVMEM_MIRROR) ? SZ_64K : 0,
+ .devmem_only = atomic && IS_DGFX(vm->xe) &&
+ IS_ENABLED(CONFIG_DRM_XE_DEVMEM_MIRROR),
};
struct xe_svm_range *range;
struct drm_gpusvm_range *r;
struct drm_exec exec;
struct dma_fence *fence;
struct xe_tile *tile = gt_to_tile(gt);
+ int migrate_try_count = ctx.devmem_only ? 3 : 1;
ktime_t end = 0;
int err;
@@ -777,23 +811,26 @@ int xe_svm_handle_pagefault(struct xe_vm *vm, struct
xe_vma *vma,
return PTR_ERR(r);
range = to_xe_range(r);
- if (xe_svm_range_is_valid(range, tile))
+ if (xe_svm_range_is_valid(range, tile, ctx.devmem_only))
return 0;
range_debug(range, "PAGE FAULT");
- /* XXX: Add migration policy, for now migrate range once */
- if (!range->skip_migrate && range->base.flags.migrate_devmem &&
- xe_svm_range_size(range) >= SZ_64K) {
- range->skip_migrate = true;
-
+ if (--migrate_try_count >= 0 &&
+ xe_svm_range_needs_migrate_to_vram(range, vma)) {
err = xe_svm_alloc_vram(vm, tile, range, &ctx);
if (err) {
- drm_dbg(&vm->xe->drm,
- "VRAM allocation failed, falling back to "
- "retrying fault, asid=%u, errno=%pe\n",
- vm->usm.asid, ERR_PTR(err));
- goto retry;
+ if (migrate_try_count || !ctx.devmem_only) {
+ drm_dbg(&vm->xe->drm,
+ "VRAM allocation failed, falling back
to retrying fault, asid=%u, errno=%pe\n",
+ vm->usm.asid, ERR_PTR(err));
+ goto retry;
+ } else {
+ drm_err(&vm->xe->drm,
+ "VRAM allocation failed, retry count
exceeded, asid=%u, errno=%pe\n",
+ vm->usm.asid, ERR_PTR(err));
+ return err;
+ }
}
}
@@ -801,15 +838,22 @@ int xe_svm_handle_pagefault(struct xe_vm *vm, struct
xe_vma *vma,
err = drm_gpusvm_range_get_pages(&vm->svm.gpusvm, r, &ctx);
/* Corner where CPU mappings have changed */
if (err == -EOPNOTSUPP || err == -EFAULT || err == -EPERM) {
- if (err == -EOPNOTSUPP) {
- range_debug(range, "PAGE FAULT - EVICT PAGES");
- drm_gpusvm_range_evict(&vm->svm.gpusvm, &range->base);
+ if (migrate_try_count > 0 || !ctx.devmem_only) {
+ if (err == -EOPNOTSUPP) {
+ range_debug(range, "PAGE FAULT - EVICT PAGES");
+ drm_gpusvm_range_evict(&vm->svm.gpusvm,
+ &range->base);
+ }
+ drm_dbg(&vm->xe->drm,
+ "Get pages failed, falling back to retrying,
asid=%u, gpusvm=%p, errno=%pe\n",
+ vm->usm.asid, &vm->svm.gpusvm, ERR_PTR(err));
+ range_debug(range, "PAGE FAULT - RETRY PAGES");
+ goto retry;
+ } else {
+ drm_err(&vm->xe->drm,
+ "Get pages failed, retry count exceeded,
asid=%u, gpusvm=%p, errno=%pe\n",
+ vm->usm.asid, &vm->svm.gpusvm, ERR_PTR(err));
}
- drm_dbg(&vm->xe->drm,
- "Get pages failed, falling back to retrying, asid=%u,
gpusvm=%p, errno=%pe\n",
- vm->usm.asid, &vm->svm.gpusvm, ERR_PTR(err));
- range_debug(range, "PAGE FAULT - RETRY PAGES");
- goto retry;
}
if (err) {
range_debug(range, "PAGE FAULT - FAIL PAGE COLLECT");
@@ -843,9 +887,6 @@ int xe_svm_handle_pagefault(struct xe_vm *vm, struct xe_vma
*vma,
}
drm_exec_fini(&exec);
- if (xe_modparam.always_migrate_to_vram)
- range->skip_migrate = false;
-
dma_fence_wait(fence, false);
dma_fence_put(fence);
diff --git a/drivers/gpu/drm/xe/xe_svm.h b/drivers/gpu/drm/xe/xe_svm.h
index 3d441eb1f7ea..0e1f376a7471 100644
--- a/drivers/gpu/drm/xe/xe_svm.h
+++ b/drivers/gpu/drm/xe/xe_svm.h
@@ -39,11 +39,6 @@ struct xe_svm_range {
* range. Protected by GPU SVM notifier lock.
*/
u8 tile_invalidated;
- /**
- * @skip_migrate: Skip migration to VRAM, protected by GPU fault handler
- * locking.
- */
- u8 skip_migrate :1;
};
/**
--
2.34.1
